Ultra-thin wall ceramic catalytic substrate from Denso

22 December 1999

Denso Corporation, with North American headquarters in Southfield, MI, announced it has developed an ultra-thin wall ceramic catalytic substrate with 50 µm-thick cell walls. This product will be installed on late-model cars by Toyota Motor Corporation scheduled to be released next spring.

Thin walls of the new substrate reduce the flow resistance and exhaust gas pressure loss, compared with traditional products. Large cell density of 900 cells per square inch (cpsi) provides high geometric surface area, which improves treatment efficiency of exhaust emissions. The substrate is manufactured by extrusion followed by drying and baking.

Most of today's commercial ceramic substrates have wall thickness of 100-150 µm. Metallic substrates, which are characterized by thinner walls than their ceramic counterparts, have walls from 30 to 50 µm. Cell densities of commercial automotive catalyst substrates range from 400-600 cpsi.

The ultra-thin wall ceramic substrate utilizes three inventions to be patented by Denso:

A technique for mold-making to extrude very thin, 50 µm cell walls;

A technique for reinforcing the area around the substrate to counteract the loss of substrate strength resulting from thinner walls, and

A technique for reinforcing the substrate's end face to prevent erosion.

Another joint development with Toyota resulted in the development of the following three new substrates:

A 150 µm wall thickness hexagonal cell substrate,

A 100 µm hexagonal cell substrate, and

A 75 µm square cell substrate.

The last two devices are installed in the new Toyota Crown model (hexagonal type installed in gasoline direct injection engines) which was introduced in September.

Headquartered in Japan, Denso Corporation employs worldwide over 72,000 people in 25 countries. Sales for fiscal year 1998 totaled $14.5 billion. In North America, Denso employs more than 11,000 people. North American consolidated sales for 1998 totaled $3.1 billion.